Method of forming nonwoven articles by fusing strands to a base

ABSTRACT

1. A METHOD OF BONDING MELTABLE MATERIAL TO A RECEPTIVE BASE WHICH COMPRISES (A) PASSING AT LEAST ONE STRAND OF SAID MATERIAL THROUGH A HOLLOW, TUBULAR PASSAGE AND THROUGH A RESTRICTED EXTREMITY THEREOF TO PROJECT SAID MATERIAL SLIGHTLY BEYOND SAID EXTREMITY, (B) MELTING AT LEAST A PORTION OF THE PROJECTING MATERIAL, (C) CONTACTING THE THUS MELTED MATERIAL WITH SAID RECEPTIVE BASE TO BOND SAID MATERIAL TO SAID BASE, AND (D) SEPARATING THE PASSAGE AND BASE TO DRAW SAID MATERIAL THROUGH SAID PASSAGE.

y 25, 1971 H. 0. BOULTINGHOUSE METHOD OF FORMING NONWOVEN ARTICLES BY FUSING STRANDS TO A BASE Filed Dec. 2. 1966 n a l6 20 30 I I8 29' D I'- ZZZ: 27

FIG. 5

FIG. 2

INVENTOR. H. D. BOULTINGHOUSE A T TORNEYS United States Patent 3,580,761 METHOD OF FORMING N ONWOVEN ARTICLES BY FUSING STRANDS TO A BASE Harold D. Boultinghouse, Bartlesville, Okla., assignor to Phillips Petroleum Company Filed Dec. 2, 1966, Ser. No. 598,682 Int. Cl. D04h 11/00 U.S. Cl. 156-72 Claims This invention relates to nonwoven articles. In one aspect one or more strands of fusible material are compressed at one extremity and fused to a receptive base. In another aspect tufts of meltable material are physically bonded to a compatible, fusible base by compressing one or more strands of meltable material at one extremity and fusing that extremity to the compatible base. In another aspect one or more strands of heat fusible material are fed through a hollow tubular needle to compress the extremities thereof. In another aspect tufts of heat fusible material are physically bonded to a substrate having a roughened surface or open surface porosity by compressing one end thereof and fusing it to said substrate.

Natural and synthetic elastomeric materials have found application in the production of nonwoven composite sheets, webs, and decorative articles. I have now found a new method for producing such products from a variety of fusible materials.

It is therefore one object of this invention to produce nonwoven composite articles. It is another object of this invention to produce tuft composite sheet material. It is yet another object of this invention to provide a simplified method of fusing meltable material to desired backing. It is another object of this invention to provide apparatus for fusing meltable materials to receptive base stock.

In accordance with one embodiment of this invention, meltable material is fused to a receptive backing by compressing one or more strands of such material at one extremity and contacting a base material with the compressed melted extremity or extremities of the one or more strands and allowing the extremities to become attached to the base material. Once the extremity of the strand or strands has become physically attached to the base material, it can be cut into the desired length to produce either a pile fabric or decorative article as desired.

Essentially any fusible strand material can be employed within the concept of this invention. For example, natural or synthetic fusible elastomers or thermoplastics can be employed. Crystalline polymers of l-olefins, particularly polypropylene and polyethylene are very acceptable in this application.

The base material can be essentially any composition structure or design to which the meltable strands can be fused. Although laminar webs or backings probably find greater application than do other structural configurations, although essentialy any structure, e.g., three dimensional form, can be used. It is only necessary that the substrate or backing material be either capable of fusing with the strand composition or that its surface be porous or roughened so that a physical or structural bond can be formed between the fused stand extremities and the backing surface. Suitable backing materials are, for example, essen tially any natural or synthetic woven or unwoven Web stock, compatible, fusible material of any structure, perfo rated or roughened materials, such as cardboard, wood, synthetic sheeting metals, etc., natural or synthetic organic or inorganic structures having surface porosity, such as foams, granular aggregates, etc.

The concept of this invention can be best understood by reference to the drawings, which are intended only to be illustrative of one embodiment of this invention.

FIG. 1 illustrates a cross-sectional view of a presently 3,580,761 Patented May 25, 1971 preferred tuft-forming needle; FIG. 2 illustrates a crosssectional view of a similar tuft-forming needle having the facility for accommodating a multiplicity of strands or strand composites; FIG. 3 illustrates the tubular needle of FIG. 1 in addition to the loose and compresed strand; FIG. 4 illustrates a combination apparatus for producing a pile fabric; and FIG. 5 illustrates another view of the apparatus of FIG. 4.

Referring now to FIG. 1, there is provided a hollow tubular needle 1, internal passage 34, restricted opening at one extremity 2, a second opening or inlet 3 and axial extension 6. The restricted opening 2 is preferably of a diameter substantially less than the internal diameter of internal passage 34 which is in turn preferably smaller than inlet passage 3. Inlet opening 3 can also be provided with suitable beveled guide means 4 for facilitating the entrance of one or more strands of material as hereinafter detailed.

It should be pointed out that throughout the disclosure and claims of this application that the strand material employed in this invention is intended to include all crosssectional shapes of indefinite length material that can be manipulated in the manner described. Such materials are, for example, filaments, fibers, ribbons, fibrillated or unfibrillated oriented filaments, fibers, ribbons, or rods. All of these materials can be either foamed or unfoamed, although larger cross-sectional areas of foamed products can, of course, be employed. For example, either single or multiple foamed rods or heavy filaments can be passed through the needle of FIG. 1 with the only limitation being that they are capable of sutficient compression to allow their passage through the restricted passage or exit to illustrate it in FIG. 1. To compensate for the use of such heavy materials or heavy loading in normal applications, the lower extremity of hollow needle 1 can be made flexible through the provision of several longitudinal slits 5 to :allow expansion of restricted passage 2 when necessary.

The hollow needle can also be provided with two or more openings 8 and 9, as illustrated in FIG. 2. This modification enables the use of two or more strands or combinations of strands of materials simultaneously to form tufts comprising combinations of dissimilar materials.

As illustrated in FIG. 3 the strands, ribbons, etc. or combination thereof 33 enter inlet opening 3 in the hollow tubular needle 1 are compressed together in the restricted extremity of the needle and emanate from restricted opening 2 in the form of a compressed bundle 32.

In operation the compressed bundle 32 projecting slightly beyond restricted extremity 2 is melted and forced into intimate contact with the desired backing material by forcing needle 1 against the backing. The melted strands forming the compressed bundle are thus welded together and the additional melted material is caused to disperse intimately over the surface of the desired backing or throughout the porosity thereof depending, of course, on the structure of the backing material.

One [form of apparatus suitable for producing tuft material within the concept of this invention is illustrated schematically in FIGS. 4 and 5. The desired backing material can be removed from roll 26 and passed through a suitable series of rolls 35, 36 and 28 to control the intermittent motion thereof. Sprigging arm 18 housing a multiplicity of hollow needles 20 is pivotably mounted by flange 21 on base 38. The desired strands of meltable material 17 are passed to needles 20 from storage 16. The compressed bundle 32 in FIG. 3 is melted and brought into intimate contact with backing 25 by forcing needles 20 against the backing through the action of sprigging arm 18. After the melted material has at least partially solidified to backing 25 in order to provide a sufiicient bond therewith, the

sprigging arm 18 is raised thereby pulling strands 17 through the needles 20. The sprigging arm is raised to a predetermined elevation at which time mobile cutting edge 31 actuated by lever 22 and suitable operating means, such as air cylinder 27, is forced against stationary cutting blade 19 to sever the bonded tufts in predetermined lengths and at the same time, leaving the desired length of compressed bundle 32 projecting slightly beyond the restricted extremities 2 of each needle. The sprigging arm 18 is then raised to the position illustrated in FIG. 5 and the projecting bundles 32 are contacted with heating element 30 to eflect the melting thereof. Heating element 30 can be essentially any heating means capable of transferring sufiicient heat'to the projecting bundles to melt the same. For example, the heating element can be a resistive heater or simply a meltblock which is heated by other means, such as an oven in its retracted position. The heating element, mounted on swinging arm 29, is then retracted and the cycle is repeated by again forcing needles 20 against backing material 25 through the action of sprigging arm During the above-described operations, backing material 25 is shifted, preferably intermittently, to remove the tuft material from the area of contact and to expose fresh backing.

Various color combinations and/or patterns can be produced by feeding strands of different color or compositions to the several needles 20. Several sprigging arms 18 can be provided, each housing one or more of the needles 20 to provide the additional facility of intermittently spacing tufts either longitudinally or laterally, as desired, to produce patterns of varying configuration.

EXAMPLE A fibrous yarn comprising a multiplicity of polypropylene fibers were passed through a single bore needle of stainless steel having an inside diameter of inch and a reduced diameter at the restricted extremity of A inch. /a inch of the thus compressed bundle of filaments protruding from the restricted extremity was melted by using an open flame torch after which this material, in the melted state, was forced against and welded to a backing comprising melt spun polypropylene fiber coated with radial teleblock copolymer. After the melted material had solidified, the needle was withdrawn from the backing thereby pulling additional yarn through the needle which was cut to produce tufts 1% inches long and to leave about A: inch of compressed fibers extending from the restricted extremity of the needle. This operation was repeated to position tufts of bonded material on A inch center spacing to produce an extremely rugged carpet- 4 like material. Similar articles were produced using ribbons and fiber strands of fibrillated and unfibrillated polypropylene and polyethylene bonded to perforated cardboard and partially fibrillated polypropylene films.

Numerous variations and modifications of the concept of this invention will be apparent to one skilled in the art in view of the foregoing disclosure, the drawings, and the appended claims to this invention, the essence of which is that one or more strands of meltable material are compressed together at one extremity, melted and forced into intimate contact with a receptive base or backing to form a secure bond therebetween.

I claim:

1. A method of bonding meltable material to tive base which comprises (a) passing at least one strand of said material through a hollow, tubular passage and through a restricted extremity thereof to project said material slightly beyond said extremity,

(b) melting at least a portion of the projecting material,

(c) contacting the thus melted material with said receptive base to bond said material to said base, and

(d) separating the passage and base to draw said material through said passage.

2. The method of claim 1 wherein said material is severed slightly beyond said extremity after said drawing step to form a projection of said material extending slightly beyond said extremity.

3. The method of claim 1 wherein said material passed through said restricted extremity comprises a multiplicity of strands which are compressed together on passing through said restricted extremity.

4. The method of claim 1 wherein said passage is defined by the interior wall of a tubular needle having a reduced internal diameter at said restricted passage.

5. The method of claim 1 'wherein said material is thermoplastic and said receptive base has open internally communicating porosity.

a recep- References Cited UNITED STATES PATENTS 3,145,446 8/1964 Sussman 156-72X 3,266,969 8/1966 Makan-si 156-72X FOREIGN PATENTS I 1,047,382 11/1966 Great Britain 156-72 BENJAMIN R. PADGE'IT, Primary Examiner US. Cl. X.R. 

1. A METHOD OF BONDING MELTABLE MATERIAL TO A RECEPTIVE BASE WHICH COMPRISES (A) PASSING AT LEAST ONE STRAND OF SAID MATERIAL THROUGH A HOLLOW, TUBULAR PASSAGE AND THROUGH A RESTRICTED EXTREMITY THEREOF TO PROJECT SAID MATERIAL SLIGHTLY BEYOND SAID EXTREMITY, (B) MELTING AT LEAST A PORTION OF THE PROJECTING MATERIAL, (C) CONTACTING THE THUS MELTED MATERIAL WITH SAID RECEPTIVE BASE TO BOND SAID MATERIAL TO SAID BASE, AND (D) SEPARATING THE PASSAGE AND BASE TO DRAW SAID MATERIAL THROUGH SAID PASSAGE. 